Process of and apparatus for refrigeration.



F. W. WOLF.

PROCESS 0F AND vAPPARATUS FOR REFRIGERATION.

APPLICATION FILED APR. 8. 1916.

Patented .Ian.14.,1919.

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specification of Letters Patent.

Patented dan; lld", lttllw.,

application nledzdprl u, tutti. teriatlto. tatto.

fr, .chl-whom it mayooaoern: Be it known that ll, FnnuW. Worm, a citizenof the United States, and a resident of Chicago, in the county of @ookand State of lllinois, have invented certain new and usefulllmprovementsin Processes of and Apparatus for Refrigeration, and' l dohereby declare that the following is a full, clear, and enactdescription thereof, reference being had to the accompanying drawings,and to the letters of reference marked thereon, which form a part. ofthis specification.

'lhis invention relates to an improved methodof refrigeration and to anapparatus for carrying out said method and consists of the mattershereinafter described and more particularly pointed out in the appendedclaims. l

'lllhe improved method is carried on in an apparatus of the compressiontype as distingnished from absorption systems and in.

cludes the usual compressor, a condenser, an expansion chamber and a.reducing valve-connecting the condenser with the expansion chamber.'l`he improved method and apparatus are primarily intended for smallunits capable of use for domestic purposes and the object of theinvention is to ohviate the essential defects and disadvantages to befound in all compression systems as manufactured for refrigeration on alarge scale or for the manufacture of ice for commercial purposes.

@ne disadvantage which is found in the compression system results fromthe leakage at the stuling box in the compressor whichis the one openingconnecting the interior of the refrigerating apparatus with the outsideair. llf the apparatus is designed to run in pressure, a. leak in thestumng box results in a gradual loss of the refrigerant. lf the machineis designed to run in vacuum, there is a leakage of air and of themoisture cary into the apparatus through the stug box, with a resultingloss of the emciency ofthe apparatus. 'lhese-disadvanu tages are not ofserious moment in large systems when an engineer is employed to lookafter the apparatus and attend tothe l box, but in a: small,automatically controed apparatus, a tendency, to, leak im the stumngbonis prohibitive of its use.

Another disadvantage of anyrefrigerating apparatus when applying, it todomestic use is the necessity for cooling Water to cool the condenser.'lhere is not only. the enpense involved but also the cumbersomeness ofthe apparatus required for, cooling, the didiculty' in the control ofthe cooling water andofits final disposal.

My new refrigeration system and process are designed to do away withboth of these diculties, dispensing with the necessity for the use ofcooling water. on the one handand preventing either an inward or outwardflow through the stufng bor.` on the other hand.

lnV carryingl out. my invention ll. make use of an expansion valve whichis controlled by, the pressure of the atmosphere, thus maintaining thelow pressure side of the system at a pressure substantially equalto thatof the atmosphere no matter at what altitude the system isused nor howsaid pressure varies under varying climatic or barometric conditions.Since the pressure in the stumng loon is the sameas that of theatmosphere, there` is no tendency either for the outside air to dowthrough the stumng hon into the sy m or for the refrigerant toescapethrough the stung box into the outer air. Such an arrangement also hasthe addedadvantage that no adjustment of the valve is necessary, and theobjections due tothe use of springs, weights or like adjusting devicesinthe apparatus is entirely done away with.

lln addition ll select a refrigerant which boils at atmospheric pressureat a sumciently low degree below the'freezing point to produce thetemperature required in the or# dinary domestic refrigerator4 atatmospheric pressure. d refrigerant boilingfatV about ld to l5 degreesabove zero l?. at the pressure of atmosphere at sea level gives the bestresults. ll have found that a most satisfactory and in fact therefer-red refrigerant for the purpose issu fur dioXid which boils atatmospheric pressure at ldc Fahrenheit.

lSince the expansionl valve is controlled by atmospheric pressure, thepressure in the condenser and its correspondingl temperature areaterial.

llnv the accompanying drawings,2 l have illustrated diammatlcally, aan,apparatus tall dit

ltltl embodying my improved system by means of which the improvedlprocess may be carried out.

ln the drawings:

A Figure 1 illustrates a diagrammatic view of a refrigerating apparatusdesigned to carry out my improved process.

Fig. 2 illustrates a transverse vertical section on an enlarged scalethrough the compresser forming a part of the apparatus.

Fig. 3 illustrates a vertical section through the valve controlling theflow of refrigerant from the condenser coil to the expansion coil, suchvalve being generally termed an expansion valve.

Referring now to the drawing, 5 indicates a compressor having a drivenpulley 6, adapted for the operation thereof. Said pulley is operativelyconnected by means of one or more belt-s 7, to the driving pulley of amotor, 8. The driven pulley 6, is made heavy so as to act also as a flywheel and the spokes thereof are preferably constructed to form fanlike, spiral blades which act to produce a draft in the vicinity of thecompressor and to e'ecta continual change of atmosphere in and about theapparatus.

l0 indicates the condenser coil which, in this instance, is made oftubing having a comparatively small cross section and a com partivelythin wall. The inlet end, 10, of said coil is connected to the cylinderhead 9, of the compressor in such manner as to receive the compressedrefrigerant therefrom. The outlet end, 10b, of said coil is connected tothe inlet end 11a, of an expansion coil 11 by means of an expansionvalve 12, which valve controls and regulates the amount of refrigerantadmitted to said expansion coil. The outlet end, 11b, of said expansioncoil is connected to the crank case of the compressor. f

The compressor 5, comprises a crank case '13, to which is attached thecylinder, 14,

having the head 9, before mentioned. The crank case 13, has provided inone wall a blind or'c-losed bearing 15, for one end of a crank shaft 16.The other end of said crank shaft has bearing in and project-s through aremovable plate, which formsa wall 15a, of

vthe crank case and a stuilng box 17, of

familiar construction is provided about the shaft bearing.

16al indicates a crank arm and 18 a connecting rod, which is attached toa Wrist pin 19, of`a piston 20, adapted for reciprocating movement inthe cylinder 14. In the piston is provided a spring-controlled inletvalve, 21. of familiar construction.

At the upper end of the cylinder 14, is formed a valve seat 22, and 23indicates a spring-controlled valve plug of a diameter substantiall)vequal to that of the cylinder which coacts with said seat and controlsthe outlet of the compressed refrigerant from mense/r the cylinder'. 24indicates a coiled spring, interposed between said valve and cylinderhead 9,

rlhe operation of said compressor is as follows: The crank case intowhich the outlet end, 11", of the expansion coil, 11, discharges, isfilled, like the expansion coil, with expanded refrigerant atsubstantially atmospheric pressure. As the pressure in the crank case ishigher than that within the cylinder at the end of the down stroke ofthe piston, said pressure will cause the inlet valve 21, in the pistonto open and the refrigerant will pass from the crank case into the.cylinder. Upon the equalization of the pressure which will occur just asthe piston starts on its upward movement, said valve will close. Furtherupward movement of the piston will compress the expanded gas between theoutlet valve 23 and the top of the piston until the pressure therein isgreat enough to lift the outlet or discharge valve 23, against thecombined action of the spring, 24.-, and the back pressure from thecondenser coil. fter the compressed gas has been forced into thecondenser coil, the discharge or outlet valve, will again be seated. Thehot, compressed gas delivered to the condenser coil is cooled andliquefied and delivered to the expansion valve l2, as before described.

The expansion valve 12, as illustrated in the drawings, comprises acircular chambered plate 25, and a flat ring 26, which coincide at theirperipheral edges. Said plate and ring are attached together by means ofscrews, 27, and clamped between them is a disk or diaphragm 28, of thinflexible metal, a packing ring 29, being interposed between the marginalpart of the diaphragm 28, and the plate 25, to insure a gastightconnection between them.

The bot-tom of the plate 25, is concave and forms a shallow chamber 25,above the diaphragm. On the top of said plate is formed a boss, 30,having a vertically extending passage 303, which is locatedconcentrically with respect to the diaphragm 28, and which is adapted toreceive the outlet end 10h, of the condenser coil and constitutes theinlet to the said expansion valve. 31 indicates the lower end of saidpassage which opens into the chamber 25, above the diaphragm. Thischamber 25 is normally closed off from the inlet end of said passage bymeans of a valve 32, having a. head 33, adapted to close on an annularseat 8l, formed in said passage.

The valve 32, has a stem 35, which is threaded through the diaphragm 28,and through relatively dat nuts 36-37, placed on opposite sides ofdiaphragm, to rigidh` connect the valve stem thereto. A lead washer 38,is preferably interposed between the bottom surface of the diaphragm andthe nut 37, to prevent leakage in the contemperature of about 26 naanasanection betvveen the valve stem and diaphragm.

lin the boss 30, is formed a transverse passage 40, Which constitutesthe. outlet of the expansion valve and into which the inlet end l1a ofthe expansion coil 1]. is threaded. This passage is connected by meansof a passage, 4l, With the chamber 25a above the ia hragm.

ondenser pressure Will, of course, always maintain on the head 33, lofthe valve 32. The pressure in the expansion coil Will be exerted on thetop of the diaphragm, 28, While atmospheric pressure will maintainagainst the bottom side of said diaphragm. Thus the operation of thediaphragm will depend upon the did'erential of pressure between theatmosphere and the pressure in the expansion coil. The atmosphericpressure being constant, naturally the opening and closing of the valvewill depend upon the variation of the pressure in the expansion coil.The large dierence in area between that of the valve head, 33, and thetop surface of the diaphragm, 28, which is influenced by pressure in theexpansion coil, Will thus make the valve very sensitive to every slightvariation in the pressure of the expansion coil upon one side or theother of a certain pressure.

The expansion valve as illustrated herein is designed more particularlyfor use in connection with a refrigerating apparatus in Which S02 isused as the refrigerant. This for the reason that in the case of SU, aF. in the chamber in which the expansion coil is located corresponds toabout 15 1F. of temperature in the expansion coil itself and thistemperature corresponds to substantially atmospheric pressure in theexpansion coil. Thus the pressure of the atmosphere on the bottom of thediaphragm may be made use of as the constant pressure 1n producing adiderential pressure on the diaphragm, thus doing away with springs,Weights and similar devices, which While intended to be constant, arefor various reasons not constant in their action and require adjustment.

While inthe above ll have referred to SU, as the refrigerant, it will beunderstood that the apparatus is equally capable of use to the sameadvantage With other refrigerants, it being simply necessary in the caseof the use of such refrigerant to so design the apparatus that it willoperate to produce thev required temperature in the compartment in whichthe expansion coil 1s located With approximately zero pounds gage oratmospheric pressure in the expansion coils.

lFr-om what has been said, it will be manifest that in the processcarried on in the apparatus as described, the refrigerant duid, sulfurdioxid (S02) is compressed in the compressor in the usual manner. Fromthe condenserthe Huid is admitted. to the expansion coil by theexpansion valve, which operates at approximately zero pounds gagepressure or atmospheric pressure, so that the low side of the system ismaintained substantially at atmospheric or zero pounds gage pressureWhile the apparatus is in operation. Thus the refrigerant returned tothe compressor, being at atmospheric pressure, will n ot tend to leakout through stud"- ing boxes provided` in connection with the movingparts thereof, nor will the outside air tend to leak in. The operationof this apparatus and the process are entirely independent of thepressure in the high side of the system, that is in the condenser. Thus,air alone With a suitable condenser coil for producing suicientradiation, may be conveniently used for cooling the refrlgerant.

T claim as my invention:

l. A. process of refrigeration consisting in compressing a refrigerant,cooling the compressed refrigerant, expanding the cooled refrigerantinto an expansion chamber and maintaining the refrigerant Within saidchamber at substantially atmospheric pressure for the purpose set forth.

2.. d process of refrigeration consisting in compressing sulfur dioxid,cooling the compressed duid, expanding the cooled Huid into an expansionchamber, and maintaining the duid Within said chamber at substantiallatmospheric pressure for the purpose set orth.

3. di process of refrigeration consisting in compressing a refrigerant,Cooling the compressed refrigerant', expanding the cooled refrigerantinto a chamber when the pressure therein falls below substantiallyatmospheric pressure and returning the expanded refrigerant to berecompressed.

4t. Tn a refrigerating apparatus having means to compress a refrigerant,means to cool the compressed refrigerant, and an expansion chamber allconnected to form a closed circuit for the refrigerant; the improvementcomprising means to expand the cooled compressed refrigerant into saidchamber When the pressure therein falls below substantially atmosphericpressure for the purpose described, f

Tn testimony, that ll, claim the foregoing as my invention-T ax mysignature' in the presence of tvvo Witnesses, th1s 21st day of March A.D. T916. FRED W. WULF.

